define([
    'jquery',
], function (require, factory) {
    'use strict';

    class Front {
        constructor(selector,scrollHeight=900) {
            this.container = $(selector);
            this.scrollHeight=scrollHeight;
        }
        bindEvent() {
            $(window).on("scroll", $.proxy(this.onScroll, this));
        }
        onScroll() {
            var sTop = $(window).scrollTop();
            this.container.css({
                display: `${sTop >= this.scrollHeight ? "block" : "none"}`
            })
        }
        init() {
            this.bindEvent();
        }
    }
    return Front;
});
